Thin film and preparation method thereof, light-emitting device and display device

Abstract

The invention discloses a thin film and a preparation method thereof, a light-emitting device and a display device, and relates to the technical field of display. The preparation method comprises the following steps: providing an inorganic particle precursor solution, wherein the inorganic particle precursor solution comprises metal salt and alkali; a substrate is provided, the inorganic particle precursor solution is arranged on the substrate, the temperature is increased to T1, heat preservation is conducted for a period of time t1, so that part of the first metal salt and alkali react to obtain amorphous phase inorganic particles, a prefabricated film is obtained, and the prefabricated film comprises the amorphous phase inorganic particles and unreacted first metal salt and alkali; and the prefabricated film is cooled to the temperature T2, heat preservation is conducted for a period of time t2, so that the unreacted first metal salt and alkali in the prefabricated film react to generate crystalline phase inorganic particles, and the thin film is obtained. The crystalline phase particles can ensure the charge transmission performance when the thin film is used as a carrier function layer; the amorphous phase inorganic particles can improve the conductivity of the thin film, promote tight combination between the thin film and an electrode, effectively improve the interface contact quality and improve the film-forming property of the thin film.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a thin film and a preparation method thereof, a light-emitting device and a display apparatus. Background Art

[0002] Currently, the widely used light-emitting devices are organic light-emitting diodes (OLEDs) and quantum dot light-emitting diodes (QLEDs). OLED has become the mainstream technology in the field of display technology due to its excellent display performance, such as self-luminescence, simple structure, ultra-thinness, fast response speed, wide viewing angle, low power consumption, and flexible display. QLED has the advantages of saturated color and adjustable wavelength of emitted light, and high quantum yield of photoluminescence and electroluminescence, and has become a strong competitor of OLED in recent years.

[0003] In a light-emitting device, the electrode is usually made of metal materials or metal oxides, such as silver, aluminum, indium tin oxide, etc., while the carrier functional layer includes a variety of materials, commonly used are polymers, metal oxides, organic small molecules, etc. In the process of stacking the electrode and the carrier functional layer together, it is necessary to maximize the contact area between the electrode and the carrier functional layer, and to improve the film quality of the carrier functional layer to ensure that the charge can be effectively transferred, thereby minimizing energy loss during the light-emitting process of the light-emitting device.

[0004] However, there are differences in the materials and surface properties of the electrodes and carrier functional layers, resulting in uneven or defective contact areas between the electrodes and the carrier functional layers, which affects the injection and transfer of electrons and holes, and even causes the functional materials to fail. In addition, since the carrier functional layer material is generally coated on the electrode surface by solution film formation during the preparation of the light-emitting device, and multiple baking treatments are required, there is also the problem of carrier functional layer film formation. In the preparation of the light-emitting device, it is necessary to form a uniform film-forming layer between the carrier functional layer and the electrode to ensure sufficient charge transfer and effective energy conversion; at the same time, it is necessary to avoid problems such as bubbles, cracks or uneven deformation in the carrier functional layer to ensure the quality and stability of the material.

[0005] At present, the film formation uniformity of carrier thin films is poor and needs to be further improved. Summary of the invention

[0006] In view of this, the present application provides a thin film and a preparation method thereof, a light-emitting device and a display device, aiming to improve the problem of poor film formation uniformity of existing thin films.

[0007] The embodiment of the present application is implemented as follows: a method for preparing a thin film, comprising:

[0008] Providing an inorganic particle precursor solution, wherein the inorganic particle precursor solution includes a first metal salt and a base;

[0009] Providing a substrate, placing the inorganic particle precursor solution on the substrate, heating it to a temperature T1, and keeping it at that temperature for a period of time t1, so that part of the first metal salt and the base react to obtain amorphous inorganic particles, and obtain a prefabricated film, wherein the prefabricated film includes the amorphous inorganic particles and unreacted first metal salt and base;

[0010] The prefabricated film is cooled to a temperature T2 and kept at the temperature for a period of time t2, so that the unreacted first metal salt in the prefabricated film reacts with the base to generate crystalline inorganic particles, thereby obtaining a thin film.

[0011] Optionally, in some embodiments of the present application, the heating rate is 50°C / min to 120°C / min; and / or

[0012] The temperature T1 is 180°C to 250°C; and / or

[0013] The time t1 is 1 min to 20 min; and / or

[0014] The cooling rate is 50°C / min to 120°C / min; and / or

[0015] The temperature T2 is 80°C to 150°C; and / or

[0016] The time t2 is 0.5h to 4h.

[0017] Optionally, in some embodiments of the present application, the heating and / or cooling devices include: a constant temperature heating table, a rapid heating and cooling test box, an ultrafast high temperature furnace, a rapid heating and cooling RTP slide rail furnace, a rapid heating and cooling muffle furnace, and a Joule heat furnace.

[0018] Optionally, in some embodiments of the present application, the first metal salt includes one or more of zinc salts, barium salts, nickel salts, titanium salts, tin salts, tantalum salts, zirconium salts, lithium salts, aluminum salts, manganese salts, indium salts, cadmium salts, molybdenum salts, tungsten salts, copper salts, gallium salts, and chromium salts; and / or

[0019] The base includes one or more of sodium hydroxide, potassium hydroxide, tetramethylammonium hydroxide, lithium hydroxide, ammonium hydroxide, ethylenediamine, ethanolamine, diethanolamine, triethanolamine, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, and tetrabutylammonium hydroxide; and / or

[0020] The inorganic particle precursor solution also includes a solvent, and the solvent includes one or more of diethylene glycol monobutyl ether, 3-methoxy-3-methylbutanol, triethylene glycol monobutyl ether, diethylene glycol dimethyl ether, ethanol, methanol, ethanol, propanol, butanol, ethylene glycol, isopropanol, glycerol, dimethyl sulfoxide, acetone, acetophenone, tetrahydrofuran, N,N-dimethylformamide, ethyl acetate, pyrrole, butyric acid, and cresol.

[0021] Optionally, in some embodiments of the present application, the first metal salt includes metal ions, the base includes hydroxide ions, and the molar ratio of the hydroxide ions to the metal ions is (1.5-3):1; and / or

[0022] In the inorganic particle precursor solution, the molar concentration of the first metal salt is 0.04 mol / L to 0.25 mol / L; and / or

[0023] In the inorganic particle precursor solution, the molar concentration of the alkali is 0.06 mol / L to 0.75 mol / L.

[0024] Optionally, in some embodiments of the present application, the inorganic particle precursor solution also includes a second metal salt, and the second metal salt includes one or more of indium salts, gallium salts, aluminum salts, magnesium salts, lithium salts, manganese salts, yttrium salts, lanthanum salts, copper salts, nickel salts, zirconium salts, cerium salts, and gadolinium salts, and the molar ratio of the first metal salt to the second metal salt is 1:(0.02~0.2).

[0025] Optionally, in some embodiments of the present application, the substrate is a light-emitting device preform, the light-emitting device preform includes a first electrode, the inorganic particle precursor liquid is disposed on the first electrode, and the film is a hole functional film or an electron functional film; or

[0026] The substrate is a light-emitting device preform, the light-emitting device preform comprises a first electrode and a light-emitting layer, the inorganic particle precursor liquid is arranged on the light-emitting layer, and the film is a hole functional film or an electron functional film.

[0027] Correspondingly, an embodiment of the present application further provides a thin film, which is prepared by the above-mentioned preparation method, and the thin film includes amorphous inorganic particles and crystalline inorganic particles.

[0028] Optionally, in some embodiments of the present application, the material of the amorphous inorganic particles includes one or more of a first doped metal oxide particle, a first undoped metal oxide particle, a IIB-VIA semiconductor material, a IIIA-VA semiconductor material, and an IB-IIIA-VIA semiconductor material; the material of the first undoped metal oxide particle includes one or more of ZnO, TiO2, SnO2, ZrO2, and Ta2O5; the metal oxide in the first doped metal oxide particle includes one or more of ZnO, TiO2, SnO2, ZrO2, Ta2O5, and Al2O3; the doping element in the first doped metal oxide particle includes one or more of Al, Mg, Li, Mn, Y, La, Cu, Ni, Zr, Ce, In, and Ga; the IIB-VIA semiconductor material includes one or more of ZnS, ZnSe, and CdS; The IA-VA group semiconductor material includes one or more of InP and GaP, and the IB-IIIA-VIA group semiconductor material includes one or more of CuInS and CuGaS; the second doped metal oxide particles, the second undoped metal oxide particles, the metal sulfide, the metal selenide and the metal nitride, the metal oxide in the second doped metal oxide particles and the metal oxide in the second undoped metal oxide particles each independently include one or more of MoO3, WO3, NiO, CrO3, CuO, Cu2O, V2O5, the doping element in the second doped metal oxide particles includes one or more of Mo, W, Ni, Cr, Cu, V, the metal sulfide includes one or more of CuS, MoS3, WS3, the metal selenide includes one or more of MoSe3, WSe3, and the metal nitride includes P-type gallium nitride; and / or

[0029] The material of the crystalline inorganic particles includes one or more of a first doped metal oxide particle, a first undoped metal oxide particle, a IIB-VIA semiconductor material, a IIIA-VA semiconductor material and an IB-IIIA-VIA semiconductor material. The material of the first undoped metal oxide particle includes one or more of ZnO, TiO2, SnO2, ZrO2 and Ta2O5. The metal oxide in the first doped metal oxide particle includes one or more of ZnO, TiO2, SnO2, ZrO2, Ta2O5 and Al2O3. The doping element in the first doped metal oxide particle includes one or more of Al, Mg, Li, Mn, Y, La, Cu, Ni, Zr, Ce, In and Ga. The IIB-VIA semiconductor material includes one or more of ZnS, ZnSe and CdS. The IIIA-VA semiconductor The material includes one or more of InP and GaP, and the IB-IIIA-VIA group semiconductor material includes one or more of CuInS and CuGaS; one or more of second doped metal oxide particles, second undoped metal oxide particles, metal sulfides, metal selenides and metal nitrides, the metal oxide in the second doped metal oxide particles and the metal oxide in the second undoped metal oxide particles each independently include one or more of MoO3, WO3, NiO, CrO3, CuO, Cu2O, V2O5, the doping element in the second doped metal oxide particles includes one or more of Mo, W, Ni, Cr, Cu, V, the metal sulfide includes one or more of CuS, MoS3, WS3, the metal selenide includes one or more of MoSe3, WSe3, and the metal nitride includes P-type gallium nitride; and / or

[0030] The average particle size of the amorphous inorganic particles is 2nm to 4nm; and / or

[0031] The average particle size of the crystalline inorganic particles is 5nm to 8nm; and / or

[0032] The thickness of the film is 20nm-60nm.

[0033] Correspondingly, an embodiment of the present application further provides a light-emitting device, comprising: a first electrode, a first carrier functional layer, a light-emitting layer, and a second electrode stacked in sequence, wherein the first carrier functional layer is prepared by the above-mentioned preparation method.

[0034] Optionally, in some embodiments of the present application, the light emitting device further includes a second carrier functional layer, and the second carrier functional layer is arranged between the light emitting layer and the second electrode.

[0035] The first carrier functional layer is an electron functional layer, and the second carrier functional layer is a hole functional layer; or

[0036] The first carrier functional layer is a hole functional layer, and the second carrier functional layer is an electron functional layer.

[0037] Optionally, in some embodiments of the present application, the materials of the first electrode and the second electrode independently include one or more of metal, carbon material and metal oxide; the metal includes one or more of Al, Ag, Cu, Mo, Au, Ba, Ca, Yb and Mg; the carbon material includes one or more of graphite, carbon nanotubes, graphene and carbon fiber; the metal oxide includes a metal oxide electrode or a composite electrode in which a metal is sandwiched between doped or undoped transparent metal oxides, and the metal oxide The material of the material electrode includes one or more of ITO, FTO, ATO, AZO, GZO, IZO, MZO and AMO, and the composite electrode includes one or more of AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, ZnS / Ag / ZnS, ZnS / Al / ZnS, TiO2 / Ag / TiO2 and TiO2 / Al / TiO2; and / or

[0038] When the first carrier functional layer is an electronic functional layer, the material of the first carrier functional layer includes one or more of first doped metal oxide particles, first undoped metal oxide particles, IIB-VIA semiconductor materials, IIIA-VA semiconductor materials and IB-IIIA-VIA semiconductor materials, the material of the first undoped metal oxide particles includes one or more of ZnO, TiO2, SnO2, ZrO2, Ta2O5, the metal oxide in the first doped metal oxide particles includes one or more of ZnO, TiO2, SnO2, ZrO2, Ta2O5, Al2O3, the doping element in the first doped metal oxide particles includes one or more of Al, Mg, Li, Mn, Y, La, Cu, Ni, Zr, Ce, In, Ga, the IIB-VIA semiconductor materials include one or more of ZnS, ZnSe, CdS, the IIIA-VA semiconductor materials include In P, GaP, the IB-IIIA-VIA semiconductor material includes one or more of CuInS and CuGaS; when the first carrier functional layer is a hole functional layer, the material of the first carrier functional layer includes one or more of second doped metal oxide particles, second undoped metal oxide particles, metal sulfide, metal selenide and metal nitride, the metal oxide in the second doped metal oxide particles and the metal oxide in the second undoped metal oxide particles each independently include one or more of MoO3, WO3, NiO, CrO3, CuO, Cu2O, V2O5, the doping element in the second doped metal oxide particles includes one or more of Mo, W, Ni, Cr, Cu, V, the metal sulfide includes one or more of CuS, MoS3, WS3, the metal selenide includes one or more of MoSe3, WSe3, and the metal nitride includes P-type gallium nitride; and / or

[0039] The material of the light-emitting layer includes 4,4'-bis(N-carbazole)-1,1'-biphenyl: tris[2-(p-tolyl)pyridine iridium(III)], 4,4',4"-tris(carbazole-9-yl)triphenylamine: tris[2-(p-tolyl)pyridine iridium], diarylanthracene derivatives, distilbene aromatic derivatives, pyrene derivatives, fluorene derivatives, TBPe fluorescent materials, TTPX fluorescent materials, TBRb fluorescent materials, DBP fluorescent materials, delayed fluorescent materials, TTA materials, TADF materials, polymers containing BN covalent bonds, HLCT materials, Exciplex luminescent materials, CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, Cd ZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe, SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSe S, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, SnPbSTe, GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs , GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, G aInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb, CuInS2, CuInSe2, AgInS2, CdSe / CdSeS / CdS, InP / ZnSeS / ZnS, CdZ One or more of nSe / ZnSe / ZnS, CdSeS / ZnSeS / ZnS, CdSe / ZnS, CdSe / ZnSe / ZnS, ZnSe / ZnS, ZnSeTe / ZnS, CdSe / CdZnSeS / ZnS, InP / ZnSe / ZnS, AMX3 and BMX3, where A is Cs+ ion, M is a divalent metal cation selected from Pb 2+ Sn 2+ , Cu 2+ 、Ni 2+ 、Cd 2+ Cr 2+ , Mn 2+ 、Co 2+ , Fe 2+ ,Ge 2+ , Yb 2+ 、Eu 2+ One or more of, X is a halogen anion selected from Cl - Br - ,I - One or more of; B is an organic amine cation selected from CH3(CH2) n-2 NH3 + or [NH3(CH2) n NH3] 2+ , where n ≥ 2; and / or

[0040] When the second carrier functional layer is prepared by the above-mentioned preparation method, the material of the second carrier functional layer includes one or more of doped or undoped zinc oxide, barium oxide, nickel oxide, titanium oxide, tin oxide, tantalum oxide, and zirconium oxide, and the doped elements include one or more of indium, gallium, aluminum, magnesium, lithium, manganese, yttrium, lanthanum, copper, nickel, zirconium, cerium, and gadolinium;

[0041] When the second carrier functional layer is an electronic functional layer, the material of the second carrier functional layer includes one or more of first doped metal oxide particles, first non-doped metal oxide particles, IIB-VIA semiconductor materials, IIIA-VA semiconductor materials and IB-IIIA-VIA semiconductor materials, the material of the first non-doped metal oxide particles includes one or more of ZnO, TiO2, SnO2, ZrO2, and Ta2O5, and the metal oxide in the first doped metal oxide particles includes ZnO, TiO2, SnO2, ZrO2, and Ta2O5. O2, ZrO2, Ta2O5, Al2O3, the doping element in the first doped metal oxide particles includes one or more of Al, Mg, Li, Mn, Y, La, Cu, Ni, Zr, Ce, In, Ga, the IIB-VIA group semiconductor material includes one or more of ZnS, ZnSe, CdS, the IIIA-VA group semiconductor material includes one or more of InP, GaP, the IB-IIIA-VIA group semiconductor material includes one or more of CuInS, CuGaS;When the second carrier functional layer is a hole functional layer, the material of the second carrier functional layer includes 4,4'-N,N'-dicarbazolyl-biphenyl, N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4"-diamine, N,N'-diphenyl-N,N'-bis(3-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine, N,N'-bis(3-methylphenyl)-N,N'-bis(phenyl)-spiro, N,N'-bis(4-(N,N'-diphenyl-amino)phenyl)-N,N'-diphenylbenzidine, 4,4',4'-tri(N-carbazolyl)-triphenylamine, 4,4',4'-tri(carbazol-9-yl)triphenylamine, trichloroisocyanuric acid, terbium-doped Phosphate-based green light-emitting materials, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene, 4,4',4'-tri(N-3-methylphenyl-N-phenylamino)triphenylamine, poly[(9,9'-dioctylfluorene-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine))], poly(4-butylphenyl-diphenylamine), poly[bis(4-phenyl)(4-butylphenyl)amine], polyaniline, polypyrrole, poly(p-phenylene vinylene), poly(phenylene vinylene), poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene vinylene], poly[2-methoxy-5-(3',7'-dimethyloctyl) [oxy)-1,4-phenylene vinylene], copper phthalocyanine, aromatic tertiary amine, polynuclear aromatic tertiary amine, 4,4'-bis(p-carbazolyl)-1,1'-biphenyl compound, N,N,N',N'-tetraaryl benzidine, PEDOT, PEDOT:PSS and its derivatives, PEDOT:PSS derivatives doped with s-MoO3, poly(N-vinyl carbazole) and its derivatives, polymethacrylate and its derivatives, poly(9,9-octylfluorene) and its derivatives, poly(spirofluorene) and its derivatives, N,N'-di(naphthalene-1-yl)-N,N'-diphenyl benzidine, spiro NPB, nano-polycrystalline diamond, microcrystalline cellulose and tetracyanoquinodimethane, doped graphene, undoped graphene, second doped metal oxide The metal oxide in the second doped metal oxide particles and the metal oxide in the second non-doped metal oxide particles independently include one or more of MoO3, WO3, NiO, CrO3, CuO, Cu2O, V2O5, the doping element in the second doped metal oxide particles includes one or more of Mo, W, Ni, Cr, Cu, V, the metal sulfide includes one or more of CuS, MoS3, WS3, the metal selenide includes one or more of MoSe3, WSe3, and the metal nitride includes P-type gallium nitride. ;

[0042] Optionally, in some embodiments of the present application, the thickness of the first electrode is 40nm to 80nm; and / or

[0043] The thickness of the first carrier functional layer is 20nm to 60nm; and / or

[0044] The thickness of the light-emitting layer is 20nm to 60nm; and / or

[0045] The thickness of the second electrode is 40nm to 80nm; and / or

[0046] The thickness of the second carrier functional layer is 20 nm to 60 nm.

[0047] Correspondingly, an embodiment of the present application further provides a display device, which includes the above-mentioned light-emitting device.

[0048] The preparation method of the film provided in the present application obtains amorphous inorganic particles by heating and preserving, and then cools and preserving to obtain crystalline inorganic particles. The film includes both amorphous particles and crystalline inorganic particles. Crystalline particles can ensure the charge transmission performance of the film as a carrier functional layer; amorphous inorganic particles have extra lone pairs of electrons, thereby improving the conductivity of the film; at the same time, amorphous inorganic particles can promote the close bonding between the film and the electrode, prevent the separation between the film and the electrode, effectively improve the interface contact quality, improve the film forming property of the film, and thus improve the luminous efficiency of the light-emitting device; in addition, amorphous inorganic particles can also weaken the agglomeration of crystalline inorganic particles, avoiding the formation of large particles that affect the uniformity and charge transport of the film. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0050] Figure 1 is a flow chart of a method for preparing a thin film provided in an embodiment of the present application;

[0051] Figure 2 is a schematic structural diagram of a light-emitting device provided in an embodiment of the present application;

[0052] Figure 3 is a schematic structural diagram of another light-emitting device provided in an embodiment of the present application;

[0053] Figure 4 is an AFM image of the electronic functional layer film provided in Example 1 of the present application;

[0054] Reference numerals:

[0055] The first electrode 10 ; the first carrier functional layer 20 ; the electron injection layer 201 , the electron transport layer 202 ; the light emitting layer 30 ; the second carrier functional layer 40 ; the hole transport layer 401 ; the hole injection layer 402 ; and the second electrode 50 . DETAILED DESCRIPTION

[0056] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application. In addition, it should be understood that the specific implementation methods described herein are only used to illustrate and explain the present application, and are not used to limit the present application.

[0057] In this application, unless otherwise stated, directional words such as "upper" and "lower" generally refer to the upper and lower parts of the device in actual use or working state, specifically the drawing direction in the accompanying drawings; while "inner" and "outer" refer to the outline of the device. In addition, in the description of this application, the term "including" means "including but not limited to". The terms first, second, third, etc. are used only as labels and do not impose numerical requirements or establish an order.

[0058] In this application, "and / or" describes the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. A and B can be singular or plural.

[0059] In the present application, "at least one" means one or more, and "plurality" means two or more. "One or several", "at least one of the following" or similar expressions refer to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can all mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, c can be single or multiple, respectively.

[0060] Various embodiments of the present application may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be understood as a rigid limitation on the scope of the present application; therefore, the range description should be considered to have specifically disclosed all possible sub-ranges and single numerical values ​​within the range. For example, the range description from 1 to 6 should be considered to have specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which apply regardless of the range. In addition, whenever a numerical range is indicated herein, it is meant to include any cited number (fractional or integer) within the indicated range.

[0061] The technical solution of this application is as follows:

[0062] First, see Figure 1 , the present application embodiment provides a method for preparing a thin film, comprising:

[0063] S11, providing an inorganic particle precursor solution, wherein the inorganic particle precursor solution comprises a first metal salt and a base;

[0064] S12, providing a substrate, placing the inorganic particle precursor solution on the substrate, heating it to a temperature T1, and keeping it at that temperature for a period of time t1, so that part of the first metal salt and the base react to obtain amorphous inorganic particles, thereby obtaining a prefabricated film, wherein the prefabricated film includes the amorphous inorganic particles and unreacted first metal salt and base;

[0065] S13, cooling the prefabricated film to a temperature T2, and maintaining the temperature for a period of time t2, so that the unreacted first metal salt in the prefabricated film reacts with the base to generate crystalline inorganic particles, thereby obtaining a thin film.

[0066] It should be noted that the amorphous inorganic particles are inorganic particles in a state where the atoms of the particles are arranged in a long-range disordered state, and correspondingly, the crystalline inorganic particles are inorganic particles in a state where the atoms of the particles are arranged in an orderly and neat manner.

[0067] The preparation method of the film provided by the present application obtains amorphous inorganic particles by heating and keeping the temperature, and then cools and keeps the temperature to obtain crystalline inorganic particles. The film includes both amorphous particles and crystalline inorganic particles. Crystalline particles can ensure the charge transmission performance of the film when it is used as a carrier functional layer; amorphous inorganic particles have extra lone pairs of electrons, which can improve the conductivity of the film; at the same time, amorphous inorganic particles can promote the close bonding between the film and the electrode, prevent the separation between the film and the electrode, effectively improve the interface contact quality, and improve the film forming property of the film; in addition, amorphous inorganic particles can also weaken the agglomeration of crystalline inorganic particles, avoiding the formation of large particles that affect the uniformity and charge transport of the film. The film provided by the present application is applied to the carrier functional layer of the light-emitting device, which can effectively improve the stability and luminous efficiency of the light-emitting device and extend the service life of the light-emitting device.

[0068] In the S11:

[0069] In some embodiments, the first metal salt includes one or more of zinc salts, barium salts, nickel salts, titanium salts, tin salts, tantalum salts, zirconium salts, lithium salts, aluminum salts, manganese salts, indium salts, cadmium salts, molybdenum salts, tungsten salts, copper salts, gallium salts, and chromium salts.

[0070] In some embodiments, the first metal salt includes one or more of chloride, nitrate, acetate, acetate, citrate, and lactate.

[0071] Exemplarily, the zinc salt includes one or more of zinc chloride, zinc nitrate, zinc acetate, zinc acetate, zinc citrate, and zinc lactate.

[0072] In some embodiments, the base includes one or more of sodium hydroxide, potassium hydroxide, tetramethylammonium hydroxide, lithium hydroxide, ammonium hydroxide, ethylenediamine, ethanolamine, diethanolamine, triethanolamine, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, and tetrabutylammonium hydroxide.

[0073] In some embodiments, the first metal salt includes metal ions, the base includes hydroxide ions, and the molar ratio of the hydroxide ions to the metal ions is (1.5-3):1, for example, (1.6-2.9):1, (1.7-2.8):1, (1.8-2.6):1, (2-2.5):1, (2.2-2.4):1, etc. Within the molar ratio range, it is beneficial for the first metal salt and the base to fully react to generate inorganic particles.

[0074] In some embodiments, the inorganic particle precursor solution also includes a solvent, and the solvent includes one or more of diethylene glycol monobutyl ether, 3-methoxy-3-methylbutanol, triethylene glycol monobutyl ether, diethylene glycol dimethyl ether, ethanol, methanol, ethanol, propanol, butanol, ethylene glycol, isopropanol, glycerol, dimethyl sulfoxide (DMSO), acetone, acetophenone, tetrahydrofuran (THF), N,N-dimethylformamide (DMF), ethyl acetate, pyrrole, butyric acid, and cresol.

[0075] In some embodiments, in the inorganic particle precursor solution, the molar concentration of the first metal salt is 0.04mol / L to 0.25mol / L, for example, 0.05mol / L to 0.24mol / L, 0.06mol / L to 0.22mol / L, 0.08mol / L to 0.2mol / L, 0.1mol / L to 0.18mol / L, 0.12mol / L to 0.16mol / L, etc. Within the molar concentration range, it is beneficial for the first metal salt to be uniformly dispersed.

[0076] In some embodiments, in the inorganic particle precursor solution, the molar concentration of the base is 0.06mol / L to 0.75mol / L, for example, 0.1mol / L to 0.7mol / L, 0.15mol / L to 0.65mol / L, 0.2mol / L to 0.6mol / L, 0.25mol / L to 0.55mol / L, 0.3mol / L to 0.5mol / L, etc. Within the molar concentration range, it is beneficial for the base to be evenly dispersed.

[0077] In some embodiments, the inorganic particle precursor solution further includes a second metal salt.

[0078] Furthermore, the second metal salt includes one or more of indium salt, gallium salt, aluminum salt, magnesium salt, lithium salt, manganese salt, yttrium salt, lanthanum salt, copper salt, nickel salt, zirconium salt, cerium salt, and gadolinium salt.

[0079] In some embodiments, the molar ratio of the first metal salt to the second metal salt is 1:(0.02-0.2), for example, 1:(0.04-0.18), 1:(0.05-0.16), 1:(0.06-0.14), 1:(0.07-0.12), 1:(0.08-0.1). It can be understood that the second metal salt can be used as a doping component of the first metal salt to prepare amorphous phase doped inorganic particles and crystalline phase doped inorganic particles.

[0080] In some embodiments, the method for preparing the inorganic particle precursor solution comprises:

[0081] Providing a first metal salt and a first solvent to obtain a first metal salt solution;

[0082] providing a base and a second solvent to obtain a base solution;

[0083] The first metal salt solution and the alkaline solution are mixed to obtain an inorganic particle precursor solution.

[0084] In some embodiments, in the first metal salt solution, the molar concentration of the first metal salt is 0.1 mol / L to 1 mol / L, for example, 0.11 mol / L to 0.19 mol / L, 0.12 mol / L to 0.18 mol / L, 0.13 mol / L to 0.17 mol / L, 0.14 mol / L to 0.16 mol / L, etc. Within the molar concentration range, it is beneficial for the first metal salt to be fully dissolved and dispersed in the first solvent.

[0085] In some embodiments, the first solvent includes one or more of diethylene glycol monobutyl ether, 3-methoxy-3-methylbutanol, triethylene glycol monobutyl ether, diethylene glycol dimethyl ether, ethanol, methanol, ethanol, propanol, butanol, ethylene glycol, isopropanol, glycerol, dimethyl sulfoxide (DMSO), acetone, acetophenone, tetrahydrofuran (THF), N,N-dimethylformamide (DMF), ethyl acetate, pyrrole, butyric acid, and cresol.

[0086] In some embodiments, in the alkaline solution, the molar concentration of the alkali is 0.1 mol / L to 1 mol / L, for example, 0.11 mol / L to 0.19 mol / L, 0.12 mol / L to 0.18 mol / L, 0.13 mol / L to 0.17 mol / L, 0.14 mol / L to 0.16 mol / L, etc. Within the molar concentration range, it is beneficial for the alkali to be fully dissolved and dispersed in the second solvent.

[0087] In some embodiments, the pH of the alkaline solution is 12-14, for example, 12.5, 13, 13.5, etc. Within the pH range, the reaction between the first metal salt and the base is promoted.

[0088] In some embodiments, the second solvent includes one or more of diethylene glycol monobutyl ether, 3-methoxy-3-methylbutanol, triethylene glycol monobutyl ether, diethylene glycol dimethyl ether, ethanol, methanol, ethanol, propanol, butanol, ethylene glycol, isopropanol, glycerol, dimethyl sulfoxide (DMSO), acetone, acetophenone, tetrahydrofuran (THF), N,N-dimethylformamide (DMF), ethyl acetate, pyrrole, butyric acid, and cresol.

[0089] In some embodiments, after the first metal salt solution and the alkaline solution are mixed, stirring is further performed to obtain an inorganic particle precursor solution.

[0090] Furthermore, in some embodiments, the stirring time is 5 min to 30 min, for example, 6 min to 28 min, 8 min to 25 min, 10 min to 22 min, 12 min to 20 min, 15 min to 18 min, etc. Within the stirring time range, the first metal salt solution and the alkaline solution are fully mixed, and the contact between the first metal salt and the alkali is promoted.

[0091] In S12:

[0092] In some embodiments, the substrate is a light-emitting device preform, the light-emitting device preform includes a first electrode 10, the inorganic particle precursor liquid is disposed on the first electrode 10, and the film is a hole functional film or an electron functional film.

[0093] In other embodiments, the substrate is a light-emitting device preform, the light-emitting device preform includes a first electrode 10 and a light-emitting layer 30, the inorganic particle precursor liquid is disposed on the light-emitting layer 30, and the film is a hole functional film or an electron functional film.

[0094] In some embodiments, the heating rate is 50°C / min to 120°C / min, for example, 55°C / min to 110°C / min, 60°C / min to 100°C / min, 65°C / min to 90°C / min, 70°C / min to 80°C / min, etc. Within the heating rate range, the inorganic particle precursor solution is heated quickly, so that part of the inorganic particle precursor solution can form amorphous inorganic particles, and the amorphous inorganic particles can improve the conductivity of the film and promote the close combination of the film and the electrode.

[0095] In some embodiments, the temperature T1 is 180° C. to 250° C., for example, 185° C. to 245° C., 190° C. to 240° C., 200° C. to 235° C., 210° C. to 230° C., 220° C. to 225° C., etc. Within the temperature range, the synthesis of amorphous inorganic particles can be promoted.

[0096] In some embodiments, the time t1 is 1 min to 20 min, for example, 2 min to 18 min, 3 min to 16 min, 5 min to 15 min, 6 min to 12 min, 8 min to 10 min, etc. Within the holding time range, all the inorganic particle precursor solutions can be prevented from forming amorphous inorganic particles.

[0097] In some embodiments, the material of the amorphous inorganic particles includes one or more of a first doped metal oxide particle, a first undoped metal oxide particle, a IIB-VIA semiconductor material, a IIIA-VA semiconductor material, and an IB-IIIA-VIA semiconductor material. The material of the first undoped metal oxide particle includes one or more of ZnO, TiO2, SnO2, ZrO2, and Ta2O5. The metal oxide in the first doped metal oxide particle includes one or more of ZnO, TiO2, SnO2, ZrO2, Ta2O5, and Al2O3. The doping element in the first doped metal oxide particle includes one or more of Al, Mg, Li, Mn, Y, La, Cu, Ni, Zr, Ce, In, and Ga. The IIB-VIA semiconductor material includes one or more of ZnS, ZnSe, and CdS. The IIIA- The VA group semiconductor material includes one or more of InP and GaP, and the IB-IIIA-VIA group semiconductor material includes one or more of CuInS and CuGaS; the second doped metal oxide particles, the second undoped metal oxide particles, the metal sulfide, the metal selenide and the metal nitride, the metal oxide in the second doped metal oxide particles and the metal oxide in the second undoped metal oxide particles each independently include one or more of MoO3, WO3, NiO, CrO3, CuO, Cu2O, V2O5, the doping element in the second doped metal oxide particles includes one or more of Mo, W, Ni, Cr, Cu, V, the metal sulfide includes one or more of CuS, MoS3, WS3, the metal selenide includes one or more of MoSe3, WSe3, and the metal nitride includes P-type gallium nitride.

[0098] In some embodiments, the average particle size of the amorphous inorganic particles is 2 nm to 4 nm, for example, 2.2 nm to 3.8 nm, 2.4 nm to 3.6 nm, 2.5 nm to 3.5 nm, 2.6 nm to 3.5 nm, 2.8 nm to 3 nm, etc.

[0099] In S13:

[0100] In some embodiments, the cooling rate is 50°C / min to 120°C / min, for example, 55°C / min to 110°C / min, 60°C / min to 100°C / min, 65°C / min to 90°C / min, 70°C / min to 80°C / min. Within the cooling rate range, the unreacted first metal salt and the base can react to form crystalline inorganic particles.

[0101] In some embodiments, the temperature T2 is 80° C. to 150° C., for example, 85° C. to 140° C., 90° C. to 135° C., 95° C. to 130° C., 100° C. to 125° C., 110° C. to 120° C., etc. Within the temperature range, the synthesis of crystalline inorganic particles can be promoted.

[0102] In some embodiments, the time t2 is 0.5h to 4h, for example, 0.8h to 3.8h, 1h to 3.6h, 1.5h to 3.5h, 1.8h to 3h, 2h to 2.5h, etc. Within the above-mentioned holding time range, a film with good crystallinity can be obtained, which promotes the transfer of charges.

[0103] In some embodiments, the heating and / or cooling devices include: a constant temperature heating table, a rapid temperature rise and fall test box, an ultrafast high temperature furnace, a rapid temperature rise and fall RTP slide rail furnace, a rapid temperature rise muffle furnace, and a Joule heat furnace.

[0104] Specifically, the rapid temperature rise and fall RTP slide rail furnace can be selected from a 1100 degree small vacuum / atmosphere rapid temperature rise and fall RTP slide rail furnace, and its specific model can be OTF-1200X-RTP-4-SL. OTF-1200X-4-RTP-SL uses short-wave infrared lamps for heating, with a maximum heating rate of up to 50°C / s. A pair of slide rails are installed at the bottom, which allows the furnace to slide from one side of the furnace tube to the other side to achieve rapid heating and rapid cooling.

[0105] The ultrafast high temperature furnace can be selected from the Padick brand, and the specific models can be ultrafast high temperature furnace 2022A, ultrafast high temperature furnace 2023A or ultrafast high temperature furnace 2023B-mini, and its fastest heating rate and cooling rate can reach 10 4 ℃ / s to 10 5 ℃ / s.

[0106] The Joule heat furnace can be selected from the Padick brand, and the specific model can be the ultra-fast high temperature furnace 2023A, whose fastest heating rate and cooling rate can reach 10 4 ℃ / s to 10 5 ℃ / s.

[0107] In some embodiments, the material of the crystalline inorganic particles includes one or more of a first doped metal oxide particle, a first undoped metal oxide particle, a IIB-VIA semiconductor material, a IIIA-VA semiconductor material, and an IB-IIIA-VIA semiconductor material. The material of the first undoped metal oxide particle includes one or more of ZnO, TiO2, SnO2, ZrO2, and Ta2O5. The metal oxide in the first doped metal oxide particle includes one or more of ZnO, TiO2, SnO2, ZrO2, Ta2O5, and Al2O3. The doping element in the first doped metal oxide particle includes one or more of Al, Mg, Li, Mn, Y, La, Cu, Ni, Zr, Ce, In, and Ga. The IIB-VIA semiconductor material includes one or more of ZnS, ZnSe, and CdS. The IIIA- The VA group semiconductor material includes one or more of InP and GaP, and the IB-IIIA-VIA group semiconductor material includes one or more of CuInS and CuGaS; the second doped metal oxide particles, the second undoped metal oxide particles, the metal sulfide, the metal selenide and the metal nitride, the metal oxide in the second doped metal oxide particles and the metal oxide in the second undoped metal oxide particles each independently include one or more of MoO3, WO3, NiO, CrO3, CuO, Cu2O, V2O5, the doping element in the second doped metal oxide particles includes one or more of Mo, W, Ni, Cr, Cu, V, the metal sulfide includes one or more of CuS, MoS3, WS3, the metal selenide includes one or more of MoSe3, WSe3, and the metal nitride includes P-type gallium nitride.

[0108] In some embodiments, the average particle size of the crystalline inorganic particles is 5 nm to 8 nm, for example, 5.2 nm to 7.8 nm, 5.5 nm to 7.5 nm, 5.8 nm to 7.2 nm, 6 nm to 7 nm, 6.2 nm to 6.5 nm, etc.

[0109] In some embodiments, the film has a thickness of 20 nm to 60 nm, for example, 22 nm to 58 nm, 25 nm to 55 nm, 30 nm to 50 nm, 35 nm to 45 nm, 40 nm to 42 nm, etc. Within the thickness range, the film is uniform and dense, and has good conductivity.

[0110] In a second aspect, an embodiment of the present application further provides a film produced by the above-mentioned film preparation method.

[0111] Third, see Figure 2and Figure 3 The embodiment of the present application also provides a light-emitting device, comprising: a first electrode 10, a first carrier functional layer 20, a light-emitting layer 30 and a second electrode 50 stacked in sequence, wherein the first carrier functional layer 20 is prepared by the above-mentioned thin film preparation method.

[0112] In some embodiments, the material of the light-emitting layer 30 includes one or more of an organic light-emitting material and a quantum dot light-emitting material.

[0113] The organic light-emitting material includes one or more of CBP:Ir(mppy)3(4,4'-bis(N-carbazole)-1,1'-biphenyl:tris[2-(p-tolyl)pyridine iridium(III)]), TCTX:Ir(mmpy)(4,4',4"-tris(carbazole-9-yl)triphenylamine:tris[2-(p-tolyl)pyridine iridium]), diaromatic anthracene derivatives, distilbene aromatic derivatives, pyrene derivatives, fluorene derivatives, TBPe fluorescent materials, TTPX fluorescent materials, TBRb fluorescent materials, DBP fluorescent materials, delayed fluorescent materials, TTA materials, TADF (thermally activated delay) materials, polymers containing BN covalent bonds, HLCT (hybridized localized charge transfer excited state) materials, and Exciplex (exciplex) light-emitting materials.

[0114] The quantum dot luminescent material includes one or more of single structure quantum dots, core-shell structure quantum dots and perovskite semiconductor materials.

[0115] The material of the single structure quantum dots, the core material of the core-shell structure quantum dots and the shell material of the core-shell structure quantum dots can be respectively selected from but not limited to one or more of the group II-VI compounds, group IV-VI compounds, group III-V compounds and group I-III-VI compounds. The II-VI group compounds include one or more of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe and HgZnSTe. The IV-VI group compounds include one or more of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, and SnPbSTe. The III-V group compound includes one or more of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs and InAlPSb. The I-III-VI group compound includes one or more of CuInS2, CuInSe2 and AgInS2.

[0116] As an example, the core-shell structured quantum dots include one or more of CdSe / CdSeS / CdS, InP / ZnSeS / ZnS, CdZnSe / ZnSe / ZnS, CdSeS / ZnSeS / ZnS, CdSe / ZnS, CdSe / ZnSe / ZnS, ZnSe / ZnS, ZnSeTe / ZnS, CdSe / CdZnSeS / ZnS and InP / ZnSe / ZnS.

[0117] The perovskite semiconductor material includes a doped or undoped inorganic perovskite semiconductor, or an organic-inorganic hybrid perovskite semiconductor. The inorganic perovskite semiconductor has a general structural formula of AMX3, wherein A is Cs + ion, M is a divalent metal cation selected from Pb 2+ Sn 2+ , Cu 2+ 、Ni 2+ 、Cd 2+ Cr 2+ , Mn 2+ 、Co 2+ , Fe 2+ ,Ge 2+ , Yb 2+ 、Eu 2+ One or more of, X is a halogen anion selected from Cl - Br - ,I - The general structural formula of the organic-inorganic hybrid perovskite semiconductor is BMX3, wherein B is an organic amine cation selected from CH3(CH2) n-2 NH3 + or [NH3(CH2) n NH3] 2+ , where n≥2, M is a divalent metal cation selected from Pb 2+ Sn 2+ , Cu 2+ 、Ni 2+ 、Cd 2+ Cr 2+ , Mn 2+ 、Co 2+ , Fe 2+ ,Ge 2+ , Yb 2 + 、Eu 2+ One or more of, X is a halogen anion selected from Cl - Br - ,I - One or more of the .

[0118] In some embodiments, the materials of the first electrode 10 and the second electrode 50 include one or more of metal, carbon material and metal oxide respectively; the metal includes one or more of Al, Ag, Cu, Mo, Au, Ba, Ca, Yb and Mg; the carbon material includes one or more of graphite, carbon nanotubes, graphene and carbon fiber; the metal oxide includes a metal oxide electrode or a composite electrode with a metal sandwiched between doped or undoped transparent metal oxides, the material of the metal oxide electrode includes one or more of ITO, FTO, ATO, AZO, GZO, IZO, MZO and AMO, and the composite electrode includes one or more of AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, ZnS / Ag / ZnS, ZnS / Al / ZnS, TiO2 / Ag / TiO2 and TiO2 / Al / TiO2. Here, “ / ” represents a stacked structure. For example, AZO / Ag / AZO represents a composite electrode including an AZO layer, an Ag layer and an AZO layer stacked in sequence.

[0119] In some embodiments, the first carrier functional layer 20 is an electron functional layer or a hole functional layer.

[0120] In some embodiments, the thickness of the first electrode 10 is 40 nm to 80 nm, for example, 42 nm to 78 nm, 45 nm to 75 nm, 48 nm to 70 nm, 50 nm to 65 nm, 55 nm to 60 nm, etc.

[0121] In some embodiments, the thickness of the first carrier functional layer 20 is 20 nm to 60 nm, for example, 22 nm to 58 nm, 25 nm to 55 nm, 30 nm to 50 nm, 35 nm to 45 nm, 40 nm to 42 nm, etc.

[0122] Further, when the first carrier functional layer 20 is an electronic functional layer, the thickness of the electronic functional layer is 20nm-60nm, for example, 22nm-58nm, 25nm-55nm, 30nm-50nm, 35nm-45nm, 40nm-42nm, etc.

[0123] When the first carrier functional layer 20 is a hole functional layer, the thickness of the hole functional layer is 30 nm to 60 nm, for example, 32 nm to 58 nm, 35 nm to 55 nm, 38 nm to 50 nm, 40 nm to 48 nm, 42 nm to 45 nm, etc.

[0124] In some embodiments, the thickness of the light emitting layer 30 is 20 nm to 60 nm, for example, 22 nm to 58 nm, 25 nm to 55 nm, 30 nm to 50 nm, 35 nm to 45 nm, 40 nm to 42 nm, etc.

[0125] In some embodiments, the thickness of the second electrode 50 is 40 nm to 80 nm, for example, 42 nm to 78 nm, 45 nm to 75 nm, 48 nm to 70 nm, 50 nm to 65 nm, 55 nm to 60 nm, etc.

[0126] In some embodiments, the light emitting device further includes a second carrier functional layer 40 , and the second carrier functional layer 40 is disposed between the light emitting layer 30 and the second electrode 50 .

[0127] The second carrier functional layer 40 may be an electron functional layer or a hole functional layer.

[0128] In some embodiments, the first carrier functional layer 20 is an electron functional layer, and the second carrier functional layer 40 is a hole functional layer.

[0129] In some other embodiments, the first carrier functional layer 20 is a hole functional layer, and the second carrier functional layer 40 is an electron functional layer.

[0130] Furthermore, the electron functional layer includes one or more of an electron transport layer 202 and an electron injection layer 201 , and the hole functional layer includes one or more of a hole transport layer 401 and a hole injection layer 402 .

[0131] In some embodiments, when the first carrier functional layer 20 is an electronic functional layer, the material of the first carrier functional layer 20 includes one or more of first doped metal oxide particles, first undoped metal oxide particles, IIB-VIA semiconductor materials, IIIA-VA semiconductor materials, and IB-IIIA-VIA semiconductor materials, the material of the first undoped metal oxide particles includes one or more of ZnO, TiO2, SnO2, ZrO2, and Ta2O5, and the metal oxide in the first doped metal oxide particles includes ZnO, T The invention relates to one or more of iO2, SnO2, ZrO2, Ta2O5, and Al2O3, the doping elements in the first doped metal oxide particles include one or more of Al, Mg, Li, Mn, Y, La, Cu, Ni, Zr, Ce, In, and Ga, the IIB-VIA group semiconductor materials include one or more of ZnS, ZnSe, and CdS, the IIIA-VA group semiconductor materials include one or more of InP and GaP, and the IB-IIIA-VIA group semiconductor materials include one or more of CuInS and CuGaS.

[0132] In other embodiments, when the first carrier functional layer 20 is a hole functional layer, the material of the first carrier functional layer 20 includes one or more of second doped metal oxide particles, second undoped metal oxide particles, metal sulfides, metal selenides and metal nitrides, the metal oxide in the second doped metal oxide particles and the metal oxide in the second undoped metal oxide particles each independently include one or more of MoO3, WO3, NiO, CrO3, CuO, Cu2O, V2O5, the doping element in the second doped metal oxide particles includes one or more of Mo, W, Ni, Cr, Cu, V, the metal sulfide includes one or more of CuS, MoS3, WS3, the metal selenide includes one or more of MoSe3, WSe3, and the metal nitride includes P-type gallium nitride.

[0133] In some embodiments, the second carrier functional layer 40 is prepared by the above-mentioned thin film preparation method.

[0134] In some embodiments, when the second carrier functional layer 40 is an electronic functional layer, the material of the second carrier functional layer 40 includes one or more of first doped metal oxide particles, first undoped metal oxide particles, IIB-VIA semiconductor materials, IIIA-VA semiconductor materials, and IB-IIIA-VIA semiconductor materials, the material of the first undoped metal oxide particles includes one or more of ZnO, TiO2, SnO2, ZrO2, and Ta2O5, and the metal oxide in the first doped metal oxide particles includes ZnO, T The invention relates to one or more of iO2, SnO2, ZrO2, Ta2O5, and Al2O3, the doping elements in the first doped metal oxide particles include one or more of Al, Mg, Li, Mn, Y, La, Cu, Ni, Zr, Ce, In, and Ga, the IIB-VIA group semiconductor materials include one or more of ZnS, ZnSe, and CdS, the IIIA-VA group semiconductor materials include one or more of InP and GaP, and the IB-IIIA-VIA group semiconductor materials include one or more of CuInS and CuGaS.

[0135] In some other embodiments, when the second carrier functional layer 40 is a hole functional layer, the material of the second carrier functional layer 40 includes 4,4'-N,N'-dicarbazolyl-biphenyl, N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4"-diamine, N,N'-diphenyl-N,N'-bis(3-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine, N,N'-bis(3-methylphenyl)-N,N'-bis(phenyl)-spiro, N, N'-bis(4-(N,N'-diphenyl-amino)phenyl)-N,N'-diphenylbenzidine, 4,4',4'-tri(N-carbazolyl)-triphenylamine, 4,4',4'-tri(carbazolyl-9-yl)triphenylamine, trichloroisocyanuric acid, terbium-doped phosphate-based green luminescent materials, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene, 4,4',4'-tri(N-3-methylphenyl-N-phenylamino)triphenylamine, poly[(9,9'- dioctylfluorene-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine))], poly(4-butylphenyl-diphenylamine), poly[bis(4-phenyl)(4-butylphenyl)amine], polyaniline, polypyrrole, poly(p-phenylenevinylene), poly(phenylenevinylene), poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene], poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylenevinylene [base], copper phthalocyanine, aromatic tertiary amine, polynuclear aromatic tertiary amine, 4,4'-bis(p-carbazolyl)-1,1'-biphenyl compound, N,N,N',N'-tetraaryl benzidine, PEDOT, PEDOT:PSS and its derivatives, PEDOT:PSS derivatives doped with s-MoO3, poly(N-vinylcarbazole) and its derivatives, polymethacrylate and its derivatives, poly(9,9-octylfluorene) and its derivatives, poly(spirofluorene) and its derivatives, N,N'-di(naphthalene-1-yl)-N,N'-diphenylbenzidine, spiro NPB, nano-polycrystalline diamond, microcrystalline cellulose and tetracyanoquinodimethane, doped graphene, undoped graphene, second doped metal oxide particles, second undoped metal oxide particles, metal sulfide, metal selenide and metal nitride, the metal oxide in the second doped metal oxide particles and the metal oxide in the second undoped metal oxide particles independently include one or more of MoO3, WO3, NiO, CrO3, CuO, Cu2O, V2O5, the doping element in the second doped metal oxide particles includes one or more of Mo, W, Ni, Cr, Cu, V, the metal sulfide includes one or more of CuS, MoS3, WS3, the metal selenide includes one or more of MoSe3, WSe3, and the metal nitride includes P-type gallium nitride.

[0136] In a fourth aspect, the present application also relates to a display device, which includes the light-emitting device.

[0137] The display device can be any electronic product with a display function, including but not limited to smart phones, tablet computers, laptops, digital cameras, digital video cameras, smart wearable devices, smart weighing electronic scales, car displays, televisions or e-book readers, among which smart wearable devices can be, for example, smart bracelets, smart watches, virtual reality (VR) helmets, etc.

[0138] The present application is described in detail below through specific embodiments. The following embodiments are only partial embodiments of the present application and are not limitations of the present application.

[0139] Example 1

[0140] This embodiment provides a light emitting device, and the preparation method is as follows:

[0141] Providing a substrate, and thermally evaporating a layer of metallic silver on the substrate to obtain a 60nm cathode;

[0142] Dissolve zinc chloride in diethylene glycol monobutyl ether to obtain a metal salt solution with a concentration of 0.5 mol / L, dissolve sodium hydroxide in diethylene glycol monobutyl ether to obtain an alkaline solution with a concentration of 0.6 mol / L, mix 10 mL of the metal salt solution with 20 mL of the alkaline solution, and stir for 0.5 h to obtain an inorganic particle precursor solution;

[0143] Spin-coat the inorganic particle precursor liquid on the cathode, heat it to 200°C at a rate of 80°C / min, keep it warm for 5 minutes, then cool it to 120°C at a rate of 80°C / min, keep it warm for 2 hours, and obtain a 30nm electronic functional layer, the material of the electronic functional layer includes amorphous zinc oxide and crystalline zinc oxide;

[0144] Dissolve CdS quantum dots in n-octane to prepare a quantum dot solution with a concentration of 15 mg / mL; use a pipette to draw 45 μL and spin-coat it on the electronic functional layer at a spin-coating speed of 3500 rpm for 45 seconds, then anneal at a temperature of 120°C for 12 minutes to obtain a 20 nm light-emitting layer;

[0145] 40 μL of PVK solution was taken with a pipette and spin-coated on the light-emitting layer at a speed of 4000 rpm for 30 seconds, followed by annealing at a temperature of 140°C for 15 minutes to obtain a 45 nm hole functional layer;

[0146] Providing an ITO glass, cleaning the ITO glass with a cleaning agent to remove stains on the surface, then ultrasonically cleaning the ITO glass with deionized water, isopropyl acetone, acetone and deionized water for 20 minutes respectively, then drying with nitrogen, and placing the ITO glass on a hole functional layer to obtain an ITO anode with a thickness of 50 nm;

[0147] The device was heat treated at 120° C. for 15 min and packaged to obtain a light-emitting device.

[0148] Example 2

[0149] This embodiment is substantially the same as Embodiment 1, except that in this embodiment, the temperature is increased to 200° C. at a rate of 50° C. / min.

[0150] Example 3

[0151] This embodiment is substantially the same as Embodiment 1, except that in this embodiment, the temperature is increased to 200° C. at a rate of 120° C. / min.

[0152] Example 4

[0153] This embodiment is substantially the same as Embodiment 1, except that in this embodiment, the temperature is increased to 180° C. at a rate of 80° C. / min.

[0154] Example 5

[0155] This embodiment is substantially the same as Embodiment 1, except that in this embodiment, the temperature is increased to 250° C. at a rate of 80° C. / min.

[0156] Example 6

[0157] This embodiment is substantially the same as embodiment 1, except that in this embodiment, the temperature is kept at 200° C. for 1 minute.

[0158] Example 7

[0159] This embodiment is basically the same as Embodiment 1, except that in this embodiment, the temperature is kept at 200° C. for 20 minutes.

[0160] Example 8

[0161] This embodiment is substantially the same as Embodiment 1, except that in this embodiment, the temperature is lowered to 120° C. at a rate of 5° C. / min.

[0162] Example 9

[0163] This embodiment is substantially the same as Embodiment 1, except that in this embodiment, the temperature is lowered to 120° C. at a rate of 30° C. / min.

[0164] Example 10

[0165] This embodiment is substantially the same as Embodiment 1, except that in this embodiment, the temperature is lowered to 80° C. at a rate of 50° C. / min.

[0166] Embodiment 11

[0167] This embodiment is substantially the same as Embodiment 1, except that in this embodiment, the temperature is lowered to 150° C. at a rate of 120° C. / min.

[0168] Example 12

[0169] This embodiment is substantially the same as embodiment 1, except that in this embodiment, the temperature is kept at 120° C. for 0.5 h.

[0170] Embodiment 13

[0171] This embodiment is substantially the same as embodiment 1, except that in this embodiment, the temperature is kept at 120° C. for 4 hours.

[0172] Embodiment 14

[0173] This embodiment is substantially the same as Embodiment 1, except that in this embodiment, zinc chloride is replaced by zirconium acetate, and the material of the electronic functional layer includes amorphous zirconium oxide and crystalline zirconium oxide.

[0174] Embodiment 15

[0175] This embodiment is substantially the same as Embodiment 1, except that, in this embodiment, 0.001 mol of magnesium acetate is further added to the inorganic particle precursor solution, and the material of the electronic functional layer includes amorphous phase magnesium-doped zinc oxide and crystalline phase magnesium-doped zinc oxide.

[0176] Example 16

[0177] This embodiment is basically the same as Embodiment 1, except that in this embodiment, the preparation order is anode, hole functional layer, light-emitting layer, an electronic functional layer is prepared on the light-emitting layer, and a cathode is prepared on the electronic functional layer.

[0178] Embodiment 17

[0179] This embodiment is basically the same as Embodiment 1, except that in this embodiment, an anode is prepared first, and a hole functional layer, a light-emitting layer, an electron functional layer and a cathode are prepared on the anode;

[0180] The preparation method of the hole functional layer is replaced by: dissolving titanium chloride in diethylene glycol monobutyl ether to obtain a metal salt solution with a concentration of 0.5 mol / L, dissolving sodium hydroxide in diethylene glycol monobutyl ether to obtain an alkaline solution with a concentration of 0.6 mol / L, mixing 10 mL of the metal salt solution with 20 mL of the alkaline solution, and stirring for 0.5 h to obtain an inorganic particle precursor solution; spin-coating the inorganic particle precursor solution on the anode, heating to 200°C at a rate of 80°C / s, keeping the temperature for 5 min, and then cooling to 120°C at a rate of 80°C / s, keeping the temperature for 2 h, to obtain a 30 nm hole functional layer, wherein the material of the hole functional layer includes amorphous titanium oxide and crystalline titanium oxide;

[0181] The preparation method of the electronic functional layer was replaced by: spin coating ZnO solution on the light-emitting layer, the spin coating speed was 3400r / min, the spin coating time was 40s, and after spin coating, annealing was performed in a nitrogen atmosphere, the annealing temperature was 100°C, the annealing time was 15min, and a 30nm electronic functional layer was obtained.

[0182] Comparative Example 1

[0183] This comparative example is basically the same as Example 1, except that the preparation method of the electronic functional layer in this comparative example is replaced by: spin coating the ZnO solution on the cathode, the spin coating speed is 3400r / min, the spin coating time is 40s, and after the spin coating is completed, annealing is performed in a nitrogen atmosphere, the annealing temperature is 100°C, and the annealing time is 15min, to obtain a 30nm electronic functional layer.

[0184] Comparative Example 2

[0185] This comparative example is basically the same as Example 14, except that the preparation method of the electronic functional layer in this comparative example is the same as that in Comparative Example 1.

[0186] Comparative Example 3

[0187] This comparative example is basically the same as Example 17, except that the preparation of the hole functional layer in this comparative example is the same as that in Example 1.

[0188] The roughness of the electronic functional layer films in Examples 1 to 14 and the comparative example, and the hole functional layer film in Example 15 were tested by atomic force microscopy to obtain an AFM image of the electronic functional layer film in Example 1. The results are shown in FIG. Figure 4 The roughness of the electronic functional layer film and the hole functional layer film is shown in Table 1.

[0189] Depend on Figure 4 It can be seen that the electronic functional layer film obtained in Example 1 has uniform thickness, is uniform and dense, and has no obvious defects, which is beneficial to improving the electron migration rate of the electronic functional layer film and its bonding with the cathode.

[0190] The maximum external quantum efficiency EQE of the light-emitting devices in Examples 1 to 15 and the comparative example was measured on the first day (1d) and the tenth day (10d). max And life T95@1k nit test, the test results are shown in Table 1.

[0191] Among them, the detection method of the maximum external quantum efficiency is: measured by LabView controlling the QE PRO spectrometer, Keithley2400, and the efficiency test system built by Keithley 6485, with a driving current of 2mA;

[0192] The test method for life span T95@1k nit is: using a 128-channel life span test system customized by Guangzhou New Vision Company. The system architecture is a constant voltage and constant current source to drive QLED, test the change in voltage or current, and the photodiode detector and test system test the brightness (photocurrent) change of QLED. The brightness meter test calibrates the brightness (photocurrent) of QLED to obtain the time it takes for the initial brightness of the light-emitting diode to decay to 95%, and the driving current is 2mA; T95@1k nit refers to the time it takes for the initial brightness of the device to decay to 95%, and it is converted to the aging time under 1k nit.

[0193] Table 1

[0194]

[0195] From Table 1, we can see that:

[0196] It can be seen from Examples 1 to 7 and Comparative Example 1 that the electronic functional layer is prepared by the thin film preparation method provided by the present scheme. Under the conditions of heating and heat preservation provided by the present scheme, the roughness of the electronic functional layer is significantly reduced. After being placed for 10 days, the luminous efficiency of the light-emitting devices of Examples 1 to 7 is still maintained at a high level, and the T95 service life is also much higher than that of the light-emitting device in the comparative example; within the range of increased heating and heat preservation conditions, the heating rate, heating temperature and heat preservation time are appropriate, which can make the thin film roughness of the light-emitting device lower, the luminous efficiency higher and the service life longer, indicating that after the inorganic particle precursor solution is set, a rapid heating treatment is performed to obtain a partial amorphous phase, so that the electronic functional layer and the cathode of the light-emitting device are still tightly combined during the long-term storage process, thereby improving the stability of the electronic functional layer and the stability of the light-emitting device;

[0197] It can be seen from Example 1, Examples 8 to 13 and Comparative Example 1 that after the inorganic particle precursor solution is heated, the temperature reduction annealing method is further adopted to significantly reduce the film roughness of the electronic functional layer, and after being placed for 10 days, its luminous efficiency and service life only slightly decrease, which is much higher than the luminous efficiency and service life of the light-emitting device in the comparative example; this is because in the process of temperature reduction annealing, the inorganic particle precursor solution is conducive to forming crystalline inorganic particles, ensuring the electron transmission efficiency of the electronic functional layer, thereby improving the luminous efficiency of the light-emitting device and extending the service life of the light-emitting device;

[0198] It can be seen from Example 1, Examples 14 to 15 and Comparative Examples 1 to 2 that no matter zinc oxide, zirconium oxide or magnesium-doped zinc oxide is used as the material of the electronic functional layer, there is no significant difference in the roughness of the film after being prepared by this scheme, and the roughness of the film is significantly reduced compared with the electronic functional layer film of Comparative Examples 1 to 2; however, the luminous efficiency and service life of the light-emitting device of Example 1 and Example 15 are better than the light-emitting device of Example 14, indicating that zinc oxide is more suitable for electronic functional materials than zirconium oxide, and there is no significant difference in the performance of the light-emitting devices using zinc oxide or magnesium-doped zinc oxide as electronic functional materials;

[0199] It can be seen from Example 1, Examples 16 to 17 and Comparative Example 1 and Comparative Example 3 that, for the light-emitting device, whether the electronic functional layer or the hole functional layer is prepared by the scheme of this scheme, there is no obvious difference in the roughness of the film, and both are lower than the roughness of the carrier functional film of the light-emitting device in the comparative example. However, the luminous efficiency and service life of the light-emitting device in which the electronic functional layer is prepared by this scheme are better than those of the light-emitting device in Example 17, indicating that this scheme is suitable for the preparation of electronic functional layers and hole functional layers, and the improvement of the performance of the light-emitting device by preparing the electronic functional layer is more obvious than that of preparing the hole functional layer; and the film roughness of preparing the electronic functional layer on the cathode is lower than that of preparing the electronic functional layer on the light-emitting layer, and the light-emitting performance of the light-emitting device is better. This is because the heating and cooling of the scheme has a certain influence on the material of the light-emitting layer, so the performance of the light-emitting device in Example 1 in which the film is directly prepared on the cathode is better.

[0200] The thin film and its preparation method, light-emitting device and display device provided in the embodiments of the present application are introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea; at the same time, for technical personnel in this field, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A method for preparing a thin film, characterized in that: include: Providing an inorganic particle precursor solution, wherein the inorganic particle precursor solution includes a first metal salt and a base; Providing a substrate, placing the inorganic particle precursor solution on the substrate, heating it to a temperature T1, and keeping it at that temperature for a period of time t1, so that part of the first metal salt and the base react to obtain amorphous inorganic particles, and obtain a prefabricated film, wherein the prefabricated film includes the amorphous inorganic particles and unreacted first metal salt and base; The prefabricated film is cooled to a temperature T2 and kept at the temperature for a period of time t2, so that the unreacted first metal salt in the prefabricated film reacts with the base to generate crystalline inorganic particles, thereby obtaining a thin film.

2. The preparation method according to claim 1, characterized in that The heating rate is 50°C / min to 120°C / min; and / or The temperature T1 is 180°C to 250°C; and / or The time t1 is 1 min to 20 min; and / or The cooling rate is 50°C / min to 120°C / min; and / or The temperature T2 is 80°C to 150°C; and / or The time t2 is 0.5h to 4h.

3. The preparation method according to claim 1, characterized in that: The heating and / or cooling devices include: a constant temperature heating table, a fast heating and cooling test box, an ultra-fast high temperature furnace, a fast heating and cooling RTP slide rail furnace, a fast heating and cooling muffle furnace, and a Joule heat furnace.

4. The preparation method according to claim 1, characterized in that: The first metal salt comprises one or more of zinc salts, barium salts, nickel salts, titanium salts, tin salts, tantalum salts, zirconium salts, lithium salts, aluminum salts, manganese salts, indium salts, cadmium salts, molybdenum salts, tungsten salts, copper salts, gallium salts, and chromium salts; and / or The base includes one or more of sodium hydroxide, potassium hydroxide, tetramethylammonium hydroxide, lithium hydroxide, ammonium hydroxide, ethylenediamine, ethanolamine, diethanolamine, triethanolamine, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, and tetrabutylammonium hydroxide; and / or The inorganic particle precursor solution also includes a solvent, and the solvent includes one or more of diethylene glycol monobutyl ether, 3-methoxy-3-methylbutanol, triethylene glycol monobutyl ether, diethylene glycol dimethyl ether, ethanol, methanol, ethanol, propanol, butanol, ethylene glycol, isopropanol, glycerol, dimethyl sulfoxide, acetone, acetophenone, tetrahydrofuran, N,N-dimethylformamide, ethyl acetate, pyrrole, butyric acid, and cresol.

5. The preparation method according to claim 1, characterized in that: The first metal salt includes metal ions, the base includes hydroxide ions, and the molar ratio of the hydroxide ions to the metal ions is (1.5-3):1; and / or In the inorganic particle precursor solution, the molar concentration of the first metal salt is 0.04 mol / L to 0.25 mol / L; and / or In the inorganic particle precursor solution, the molar concentration of the alkali is 0.06 mol / L to 0.75 mol / L.

6. The preparation method according to claim 1, characterized in that: The inorganic particle precursor solution also includes a second metal salt, which includes one or more of indium salts, gallium salts, aluminum salts, magnesium salts, lithium salts, manganese salts, yttrium salts, lanthanum salts, copper salts, nickel salts, zirconium salts, cerium salts, and gadolinium salts, and the molar ratio of the first metal salt to the second metal salt is 1:(0.02~0.2).

7. The preparation method according to claim 1, characterized in that: The substrate is a light-emitting device preform, the light-emitting device preform comprises a first electrode, the inorganic particle precursor liquid is arranged on the first electrode, and the film is a hole functional film or an electron functional film; or The substrate is a light-emitting device preform, the light-emitting device preform comprises a first electrode and a light-emitting layer, the inorganic particle precursor liquid is arranged on the light-emitting layer, and the film is a hole functional film or an electron functional film.

8. A film, characterized in that: The film is prepared by the preparation method according to any one of claims 1 to 7, and comprises amorphous inorganic particles and crystalline inorganic particles.

9. The film according to claim 8, characterized in that The material of the amorphous inorganic particles includes one or more of a first doped metal oxide particle, a first undoped metal oxide particle, a IIB-VIA semiconductor material, a IIIA-VA semiconductor material and an IB-IIIA-VIA semiconductor material. The material of the first undoped metal oxide particle includes one or more of ZnO, TiO2, SnO2, ZrO2 and Ta2O5. The metal oxide in the first doped metal oxide particle includes one or more of ZnO, TiO2, SnO2, ZrO2, Ta2O5 and Al2O3. The doping element in the first doped metal oxide particle includes one or more of Al, Mg, Li, Mn, Y, La, Cu, Ni, Zr, Ce, In and Ga. The IIB-VIA semiconductor material includes one or more of ZnS, ZnSe and CdS. The IIIA-VA semiconductor The bulk material includes one or more of InP and GaP, and the IB-IIIA-VIA semiconductor material includes one or more of CuInS and CuGaS; one or more of second doped metal oxide particles, second undoped metal oxide particles, metal sulfides, metal selenides and metal nitrides, the metal oxide in the second doped metal oxide particles and the metal oxide in the second undoped metal oxide particles each independently include one or more of MoO3, WO3, NiO, CrO3, CuO, Cu2O, V2O5, the doping element in the second doped metal oxide particles includes one or more of Mo, W, Ni, Cr, Cu, V, the metal sulfide includes one or more of CuS, MoS3, WS3, the metal selenide includes one or more of MoSe3, WSe3, and the metal nitride includes P-type gallium nitride; and / or The material of the crystalline inorganic particles includes one or more of a first doped metal oxide particle, a first undoped metal oxide particle, a IIB-VIA semiconductor material, a IIIA-VA semiconductor material and an IB-IIIA-VIA semiconductor material. The material of the first undoped metal oxide particle includes one or more of ZnO, TiO2, SnO2, ZrO2 and Ta2O5. The metal oxide in the first doped metal oxide particle includes one or more of ZnO, TiO2, SnO2, ZrO2, Ta2O5 and Al2O3. The doping element in the first doped metal oxide particle includes one or more of Al, Mg, Li, Mn, Y, La, Cu, Ni, Zr, Ce, In and Ga. The IIB-VIA semiconductor material includes one or more of ZnS, ZnSe and CdS. The IIIA-VA semiconductor The material includes one or more of InP and GaP, and the IB-IIIA-VIA group semiconductor material includes one or more of CuInS and CuGaS; one or more of second doped metal oxide particles, second undoped metal oxide particles, metal sulfides, metal selenides and metal nitrides, the metal oxide in the second doped metal oxide particles and the metal oxide in the second undoped metal oxide particles each independently include one or more of MoO3, WO3, NiO, CrO3, CuO, Cu2O, V2O5, the doping element in the second doped metal oxide particles includes one or more of Mo, W, Ni, Cr, Cu, V, the metal sulfide includes one or more of CuS, MoS3, WS3, the metal selenide includes one or more of MoSe3, WSe3, and the metal nitride includes P-type gallium nitride; and / or The average particle size of the amorphous inorganic particles is 2nm to 4nm; and / or The average particle size of the crystalline inorganic particles is 5nm to 8nm; and / or The thickness of the film is 20nm-60nm.

10. A light emitting device, characterized in that: include: A first electrode, a first carrier functional layer, a light-emitting layer and a second electrode are stacked in sequence, wherein the first carrier functional layer is prepared by the preparation method according to any one of claims 1 to 7.

11. The light emitting device according to claim 10, characterized in that: The light emitting device further comprises a second carrier functional layer, wherein the second carrier functional layer is arranged between the light emitting layer and the second electrode. The first carrier functional layer is an electron functional layer, and the second carrier functional layer is a hole functional layer; or The first carrier functional layer is a hole functional layer, and the second carrier functional layer is an electron functional layer.

12. The light emitting device according to claim 11, characterized in that: The materials of the first electrode and the second electrode independently include one or more of metal, carbon material and metal oxide; the metal includes one or more of Al, Ag, Cu, Mo, Au, Ba, Ca, Yb and Mg; the carbon material includes one or more of graphite, carbon nanotubes, graphene and carbon fiber; the metal oxide includes a metal oxide electrode or a composite electrode with a metal sandwiched between doped or undoped transparent metal oxides, the material of the metal oxide electrode includes one or more of ITO, FTO, ATO, AZO, GZO, IZO, MZO and AMO, and the composite electrode includes one or more of AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, ZnS / Ag / ZnS, ZnS / Al / ZnS, TiO2 / Ag / TiO2 and TiO2 / Al / TiO2; and / or When the first carrier functional layer is an electronic functional layer, the material of the first carrier functional layer includes one or more of first doped metal oxide particles, first undoped metal oxide particles, IIB-VIA semiconductor materials, IIIA-VA semiconductor materials and IB-IIIA-VIA semiconductor materials, the material of the first undoped metal oxide particles includes one or more of ZnO, TiO2, SnO2, ZrO2, Ta2O5, the metal oxide in the first doped metal oxide particles includes one or more of ZnO, TiO2, SnO2, ZrO2, Ta2O5, Al2O3, the doping element in the first doped metal oxide particles includes one or more of Al, Mg, Li, Mn, Y, La, Cu, Ni, Zr, Ce, In, Ga, the IIB-VIA semiconductor materials include one or more of ZnS, ZnSe, CdS, the IIIA-VA semiconductor materials include In P, GaP, the IB-IIIA-VIA semiconductor material includes one or more of CuInS and CuGaS; when the first carrier functional layer is a hole functional layer, the material of the first carrier functional layer includes one or more of second doped metal oxide particles, second undoped metal oxide particles, metal sulfide, metal selenide and metal nitride, the metal oxide in the second doped metal oxide particles and the metal oxide in the second undoped metal oxide particles each independently include one or more of MoO3, WO3, NiO, CrO3, CuO, Cu2O, V2O5, the doping element in the second doped metal oxide particles includes one or more of Mo, W, Ni, Cr, Cu, V, the metal sulfide includes one or more of CuS, MoS3, WS3, the metal selenide includes one or more of MoSe3, WSe3, and the metal nitride includes P-type gallium nitride; and / or The material of the light-emitting layer includes 4,4'-bis(N-carbazole)-1,1'-biphenyl: tris[2-(p-tolyl)pyridine iridium(III)], 4,4',4"-tris(carbazole-9-yl)triphenylamine: tris[2-(p-tolyl)pyridine iridium], diarylanthracene derivatives, distilbene aromatic derivatives, pyrene derivatives, fluorene derivatives, TBPe fluorescent materials, TTPX fluorescent materials, TBRb fluorescent materials, DBP fluorescent materials, delayed fluorescent materials, TTA materials, TADF materials, polymers containing BN covalent bonds, HLCT materials, Exciplex luminescent materials, CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, Cd ZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe, SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSe S, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, SnPbSTe, GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs , GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, G aInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb, CuInS2, CuInSe2, AgInS2, CdSe / CdSeS / CdS, InP / ZnSeS / ZnS, CdZ One or more of nSe / ZnSe / ZnS, CdSeS / ZnSeS / ZnS, CdSe / ZnS, CdSe / ZnSe / ZnS, ZnSe / ZnS, ZnSeTe / ZnS, CdSe / CdZnSeS / ZnS, InP / ZnSe / ZnS, AMX3 and BMX3, where A is Cs + ion, M is a divalent metal cation selected from Pb 2+ Sn 2+ , Cu 2+ 、Ni 2+ 、Cd 2+ Cr 2+ , Mn 2+ 、Co 2+ , Fe 2+ ,Ge 2+ , Yb 2+ 、Eu 2+ One or more of, X is a halogen anion selected from Cl - Br - ,I - One or more of; B is an organic amine cation selected from CH3(CH2) n-2 NH3 + or [NH3(CH2) n NH3] 2+ , where n ≥ 2; and / or When the second carrier functional layer is an electronic functional layer, the material of the second carrier functional layer includes one or more of first doped metal oxide particles, first non-doped metal oxide particles, IIB-VIA semiconductor materials, IIIA-VA semiconductor materials and IB-IIIA-VIA semiconductor materials, the material of the first non-doped metal oxide particles includes one or more of ZnO, TiO2, SnO2, ZrO2, and Ta2O5, and the metal oxide in the first doped metal oxide particles includes ZnO, TiO2, SnO2, ZrO2, and Ta2O5. O2, ZrO2, Ta2O5, Al2O3, the doping element in the first doped metal oxide particles includes one or more of Al, Mg, Li, Mn, Y, La, Cu, Ni, Zr, Ce, In, Ga, the IIB-VIA group semiconductor material includes one or more of ZnS, ZnSe, CdS, the IIIA-VA group semiconductor material includes one or more of InP, GaP, the IB-IIIA-VIA group semiconductor material includes one or more of CuInS, CuGaS;When the second carrier functional layer is a hole functional layer, the material of the second carrier functional layer includes 4,4'-N,N'-dicarbazolyl-biphenyl, N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4"-diamine, N,N'-diphenyl-N,N'-bis(3-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine, N,N'-bis(3-methylphenyl)-N,N'-bis(phenyl)-spiro, N,N'-bis(4-(N,N'-diphenyl-amino)phenyl)-N,N'-diphenylbenzidine, 4,4',4'-tri(N-carbazolyl)-triphenylamine, 4,4',4'-tri(carbazol-9-yl)triphenylamine, trichloroisocyanuric acid, terbium-doped Phosphate-based green light-emitting materials, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene, 4,4',4'-tri(N-3-methylphenyl-N-phenylamino)triphenylamine, poly[(9,9'-dioctylfluorene-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine))], poly(4-butylphenyl-diphenylamine), poly[bis(4-phenyl)(4-butylphenyl)amine], polyaniline, polypyrrole, poly(p-phenylene vinylene), poly(phenylene vinylene), poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene vinylene], poly[2-methoxy-5-(3',7'-dimethyloctyl) [oxy)-1,4-phenylene vinylene], copper phthalocyanine, aromatic tertiary amine, polynuclear aromatic tertiary amine, 4,4'-bis(p-carbazolyl)-1,1'-biphenyl compound, N,N,N',N'-tetraaryl benzidine, PEDOT, PEDOT:PSS and its derivatives, PEDOT:PSS derivatives doped with s-MoO3, poly(N-vinyl carbazole) and its derivatives, polymethacrylate and its derivatives, poly(9,9-octylfluorene) and its derivatives, poly(spirofluorene) and its derivatives, N,N'-di(naphthalene-1-yl)-N,N'-diphenyl benzidine, spiro NPB, nano-polycrystalline diamond, microcrystalline cellulose and tetracyanoquinodimethane, doped graphene, undoped graphene, second doped metal oxide The metal oxide in the second doped metal oxide particles and the metal oxide in the second non-doped metal oxide particles independently include one or more of MoO3, WO3, NiO, CrO3, CuO, Cu2O, V2O5, the doping element in the second doped metal oxide particles includes one or more of Mo, W, Ni, Cr, Cu, V, the metal sulfide includes one or more of CuS, MoS3, WS3, the metal selenide includes one or more of MoSe3, WSe3, and the metal nitride includes P-type gallium nitride. ; 13. The light emitting device according to claim 11, characterized in that: The thickness of the first electrode is 40nm to 80nm; and / or The thickness of the first carrier functional layer is 20nm to 60nm; and / or The thickness of the light-emitting layer is 20nm to 60nm; and / or The thickness of the second electrode is 40nm to 80nm; and / or The thickness of the second carrier functional layer is 20 nm to 60 nm.

14. A display device, characterized in that: The light emitting device comprises the light emitting device as claimed in any one of claims 10 to 13.

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